The Applicant has developed a wide range of printers that use pagewidth printheads instead of traditional reciprocating printhead designs. The pagewidth designs increase print speeds as the printhead does not traverse back and forth across the page to deposit a line of an image. The pagewidth printhead simply deposits the ink on the media as it moves past at high speeds. Such printheads have made it possible to perform 1600 dpi resolution printing at speeds in the vicinity of 60 pages per minute; speeds previously not attainable with conventional inkjet printers.
The high print speeds require a large ink supply flowrate. Not only are the flow rates higher but distributing the ink along the entire length of a pagewidth printhead is more complex than feeding ink to a relatively small reciprocating printhead.
To prolong the life of the printhead, most inkjet printers will incorporate some type of maintenance facility. This may be as simple as capping the printhead when it is not in use. Capping a printhead will stop the ink on the nozzles from drying out. However it does not clean any paper dust or other contaminants that may have adhered to be nozzle face. The most effective way to remove these particles is by wiping the nozzle face with a suitable surface.
Wiping the nozzle face of printhead is an effective way of removing paper dust, ink floods, dried ink or other contaminants. However, a pagewidth printhead is difficult to wipe. While pagewidth printers with nozzle face wipers exist, the wiping mechanism is relatively slow and or complicated. Currently available pagewidth printers have several printhead ICs spaced apart from each other in the media feed direction. It is impractical for a single wiper to clean printhead ICs spaced so far apart, so each printhead ICs is wiped individually. Furthermore, the wipers move transverse to the media feed direction. This is to avoid colour mixing between nozzles of different colour. The rows of nozzles for each colour extend across the printhead ICs in a direction transverse to the media feed direction. Wiping along the row of nozzles minimises the risk of contaminating in one nozzle with ink of a different colour. However, as the printhead ICs are elongate and extend transverse to feed direction, the wiper must travel the entire length to clean all the nozzles. In light of this, the mechanism that actuates the separate wipers for each printhead ICs is complex, occupying a relatively large space and consuming a significant amount of time to complete each wiping operation.
The Applicant has developed a printhead maintenance facility that can wipe the nozzle face of pagewidth printhead in a direction parallel to the media feed direction. The ordinary worker will appreciate that the wiping member needs only travel short distance to wipe all nozzles when moving parallel to the feed direction. Consequently the wiping operation is completed much more quickly. To avoid colour mixing, the nozzles can eject ink to a blotter immediately after being wiped. As the wiping operation is completed quickly, any contaminating ink in the nozzle of different colour has very little time to diffuse into the nozzle and its associated nozzle chamber before the nozzles are fired and the ink purged.
Wiping the nozzle face of pagewidth printhead with a single, elongate wiping member can be ineffective. Inconsistent contact pressure between the wiping surface and the nozzle face can leave some parts of the nozzle face unwiped.